Accurate RMR Calculator

Find Your Resting Metabolic Rate & Calorie Intake

By: Jeremy Fox, CNC, CPTUpdated: August 18, 2023

Your metabolic rate is a crucial factor in managing your body weight and composition. Therefore, it is important to understand your metabolism to diet effectively.

Use this RMR calculator to determine the number of calories you should consume to burn fat and build muscle.

rmr calculator

Before you complete the RMR calculator, I recommend you skim through the information below. That way, you’ll understand how it works and be better prepared to put your plan into action.

What is RMR?

RMR stands for resting metabolic rate, which is a measure of the energy you expend without physical activity. In other words, it’s the number of calories your body burns when you lay on the couch all day.

BMR vs. RMR

BMR (basal metabolic rate) is often used interchangeably with RMR. The only difference is that RMR has stricter requirements when measured in the lab. For our purposes, the calculation is the same.

How to Calculate RMR

There are several different equations for calculating RMR. By far, the most common is the Harris-Benedict equation. This formula uses your gender, height, weight, and age to predict RMR.

Harris-Benedict Equation

Male: 66.47 + (6.25 x weight in lbs) + (12.71 x height in inches) – (6.755 x age)

Female: 655.1 + (4.347 x weight in lbs) + (4.07 x height in inches) – (4.676 x age)

Another way to find RMR is the Katch-McArdle equation. It uses only your lean body mass.

Katch-McArdle Equation

370 + ( 9.818 x lean mass in lbs)

Which Equation Does This RMR Calculator Use?

My RMR calculator uses a modified Katch-McArdle equation, which is more accurate because it accounts for muscle mass.

One of the most significant modifications is the addition of your somatotype or body type, which is a way to account for genetic variation in metabolic rate. For example, an endomorph naturally has a lower RMR than an ectomorph.

Accounting for genetics is a critical factor missing in most RMR calculators. And it’s just one reason this calculator is the most accurate.

What is a Normal RMR?

To establish normal resting metabolic rate (RMR) distributions, I analyzed data from over 8,000 individuals who used my RMR calculator.

RMR for women ranged from 882 to 1,997 calories with an average of 1,340 calories, while men’s RMRs ranged from 1,067 to 2,669 calories with an average of 1,806 calories.

Remember that RMR is primarily based on body mass, so if you don’t fall within the average range, that’s okay. However, a faster metabolism is desirable to burn more calories and fat.

rmr calculator female
rmr calculator male

How to Increase Your RMR

Two ways to boost your metabolism are increasing your lean body mass and gradually increasing calorie intake.

Increase Your Lean Body Mass

To gain muscle mass, it is essential to combine intense resistance training with a nutritionally balanced diet. However, consuming excessive calories can lead to unwanted body fat.

Therefore, gaining lean body mass without fat requires a marginal calorie surplus of 5-25% more calories than you burn.

How Many Calories for Muscle Gain?

Gradually Eat More Calories

Another way to increase RMR is slowly increasing the calories you eat, also called reverse dieting in the bodybuilding community. This approach is often used after a prolonged diet to rebuild metabolism.

The reason reverse dieting works is based on the principle of metabolic adaptation, where your resting metabolic rate adjusts to external energy inputs.

How to Use Reverse Dieting

Low High Metabolic Rate

Using the RMR Calculator for Calorie Intake

 To calculate the number of calories you should eat, you need to know your RMR and TDEE, which is the combination of metabolic rate and physical activity.

Moreover, TDEE calculates the number of calories required to maintain your current weight, allowing you to adjust your calorie intake based on your fitness objectives.

How to Calculate Total Daily Energy Expenditure

metabolic confusion meal plan

Get a Personalized Meal Plan

Your Custom Meal Plan does all the math and shows you exactly what to eat on workout days and rest days

Including recipes that fit your macros so you don’t even have to count calories! How’s that for easy?

Click the button below to get started.

More Tools & Calculators

If you found the information in this RMR calculator helpful, I know you’ll also be interested in using some of my other free tools and calculators. Here is a list of resources you should check out next.

Free Reverse Dieting Calculator

Simple Body Fat Percentage Calculator

Protein Intake Calculator for Fat Loss & Muscle Gain

Calorie Deficit Calculator for Sustainable Weight Loss

The Macro Calculator Everyone Is Talking About

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By |August 18, 2023|Calculators|0 Comments
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